This invention relates to the construction of elongated hollow posts for use in structural systems, and particularly to posts for use in display systems in the merchandising field and in other structural systems where decorative appearance and structural strength are important. These systems include structures and frameworks that serve as supports and backgrounds for merchandise that is offered for sale in establishments of various kinds, such as department stores and other retail stores, and for related structures in such stores.
Prior display systems of this general type have included the system shown in U.S. Pat. No. 4,133,433 in which relatively heavy extruded aluminum posts are formed with longitudinal mounting grooves in four sides. Each groove has a slotted bottom wall for receiving hook-like connecting elements of accessories such as brackets to be mounted on the posts, or similarly-shaped connecting elements on board-like struts for connection to the posts in a display structure, or a dressing room or other related structure. The grooves also are positioned and sized to receive the edges of panels that can form walls in display structures.
A lighter and less expensive post and strut construction is disclosed in U.S. Pat. No. 4,712,286 wherein a four-sided post is with longitudinal mounting groove formed by four lightweight, predecorated sheet metal strips, each bent to form one corner section of the post. This construction relied upon overlapping of the edge portions of the four corner sections within the mounting grooves for double-walled slotted bottom walls in the grooves, in an effort to provide the structural strength needed to carry the loads experienced in normal service use. Unfortunately, this double thickness of lightweight metal was not sufficient to provide the desired strength in lightweight posts.
In each of these patented systems, the struts were formed in a manner similar to the posts and provided with screw-operated tightening mechanisms for securing the posts and struts tightly together. In both the tightening mechanisms and the accessory elements, the connecting elements are of a standard type, comprising tabs that extend through the slots with notches in their undersides for fitting snugly over the slotted walls at the lower ends of the slots.
Other slot hardware systems for such accessories also exist, typically using relatively heavy sheet metal uprights in the form of tubes or mounting strips with slots sized and spaced in accordance with one of the two popular standards that are used throughout the world. One is a heavy-duty system that uses one-inch long slots spaced on two-inch centers, and the other uses one-half inch slots on one-inch centers, this frequently being used for lighter duty systems. For the heavy-duty systems, the most commonly used weight of material is eleven gauge sheet metal that is about 0.120 of an inch in thickness. The light-systems also may use eleven gauge sheet metal, or if there is no need for high load-carrying capacity, lighter and less expensive sixteen gauge sheet metal sometimes is used. This is about 0.060 of an inch thick.